Peter S. Coates Brian G. Prochazka Michael P. Chenaille Shawn T. O’Neil Steven R. Mathews Justin R. Small Katherine Miller Steve Abele Megan C. Milligan 2026 <h3 id="ddi70092-sec-0001-title" class="article-section__sub-title section1">Aim</h3><p>Population ecologists often focus on changes in the distribution and abundance of wildlife species, which are useful for trend analyses and status assessments. However, rarely are these responses evaluated simultaneously for a single species, despite their unique contributions to fully assess a species' viability. For example, focusing solely on total abundance can mask important losses in overall distribution within a metapopulation structure that may contribute to long-term population instability that results from the extirpation of small peripheral populations.</p><h3 id="ddi70092-sec-0002-title" class="article-section__sub-title section1">Location</h3><p>Bi-State region of Nevada and California, USA.</p><h3 id="ddi70092-sec-0003-title" class="article-section__sub-title section1">Methods</h3><p>We simultaneously evaluated changes in population abundance and distribution for greater sage-grouse (hereafter sage-grouse;<span>&nbsp;</span><i>Centrocercus urophasianus</i>) within the Bi-State Distinct Population Segment (DPS), a genetically distinct and isolated population straddling the border of Nevada and California. We combined population counts, demographic data, and information on space use from marked individuals to evaluate changes in population distribution and abundance over three time periods that corresponded to the three most recent population nadirs (1995–2019, 2002–2019 and 2008–2019).</p><h3 id="ddi70092-sec-0004-title" class="article-section__sub-title section1">Results</h3><p>The Bi-State DPS exhibited evidence of ~1.2%–2.5% declines annually, over the short/medium-term (1995–2019;<span> λ^</span> = 0.987, 95% CRI: 0.970–0.999), short-term (2002–2019;<span> λ^</span> = 0.975, 95% CRI: 0.963–0.985) and recent-term (2008–2019;<span> λ^</span> = 0.988, 95% CRI: 0.973–1.001). Since 1995, the spatial distribution of sage-grouse abundance in the Bi-State DPS shifted amongst subpopulations, with peripheral subpopulations suffering the largest declines.</p><h3 id="ddi70092-sec-0005-title" class="article-section__sub-title section1">Main Conclusions</h3><p>Gains in abundance and distribution amongst expanding subpopulations did not offset losses in the remaining subpopulations, with a net loss in occupied distribution of 156 km²<span>&nbsp;</span>since 1995. Reductions in spatial distribution could have implications for metapopulation persistence as peripheral populations become more vulnerable to stochastic events, which would not have been apparent from the evaluation of overall metapopulation abundance on its own.</p> application/pdf 10.1111/ddi.70092 en Wiley Changes in spatial distribution and abundance together determine potential for population persistence for greater sage-grouse article